Article of Footwear

ABSTRACT

The present invention is directed toward an article of footwear including an upper and a sole structure. The sole structure includes a generally rigid midsole plate spanning the length of the footwear and a compression member depending from the ground-facing surface of the plate. In an embodiment, the sole structure includes a forward compression member and a rearward compression member that is received into a corresponding socket formed into the midsole plate. The compression members include a plurality of compression elements interconnected by linking elements. The compression and linking elements cooperate to attenuate load forces. In an embodiment, the compression and linking elements are further configured to influence the orientation of the foot during a step cycle.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a claims priority to U.S. Provisional Application No. 62/008,075, filed 5 Jun. 2014 and entitled “Article of Footwear,” the disclosure of which is hereby incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to footwear and, in particular, footwear including an outsole with a plurality of linked pod structures.

BACKGROUND OF THE INVENTION

Athletic footwear such as running shoes is designed for comfort and durability. Runners often prefer shoes that do not restrict movement (or restrict movement to a minimal degree). It is, however, also necessary to provide a shoe that reduces fatigue and the risk of injuries caused by the different loads that arise on bones and muscles while using (e.g., running in) the footwear.

Thus, it would be desirable to provide an article footwear that protects a wearer's feet, attenuates shock, permits foot flexure, and helps to reduce load fatigue.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed toward an article of footwear including an upper and a sole structure. The sole structure includes a generally rigid midsole plate spanning the length of the footwear and a compression member depending from the ground-facing surface of the plate. In an embodiment, the sole structure includes a forward compression member and a rearward compression member that is received into a corresponding socket formed into the midsole plate. The compression members include a plurality of compression elements interconnected by linking elements. With this configuration, the compression elements are capable of moving relatively independently of each other, or at different rates of motion. The compression and linking elements cooperate to attenuate load forces. In an embodiment, the compression members cooperate to influence the orientation of the foot during a step cycle.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a front perspective view of an article of footwear in accordance with an embodiment of the invention.

FIG. 1B is a rear perspective view of the article of footwear of FIG. 1A.

FIG. 2A is a lateral side perspective view of the article of footwear of FIG. 1A.

FIG. 2B is a medial side perspective view of the article of footwear of FIG. 1A.

FIG. 3A is a lateral side view of the sole structure in accordance with an embodiment of the invention, shown in isolation.

FIG. 3B is a medial side view of the sole structure in accordance with an embodiment of the invention, shown in isolation.

FIG. 3C is a cross sectional view of the sole structure of FIG. 3B.

FIG. 4A is a top plan view of the sole structure in accordance with an embodiment of the invention, shown in isolation.

FIG. 4B is a perspective view of the article of the sole structure of FIG. 4A.

FIG. 4C is a bottom plan view of the sole structure of FIG. 4A.

FIG. 5A is a bottom plan view of an insole in accordance with an embodiment of the invention, shown in isolation.

FIG. 5B is a top plan view of the insole of FIG. 5A.

FIG. 6A is a bottom view of the forefoot compression member in accordance with an embodiment of the invention, the forefoot compression member being shown in isolation.

FIG. 6B is a bottom view of the hindfoot compression member in accordance with an embodiment of the invention, the hindfoot compression member being shown in isolation.

FIG. 6C is a schematic of the compression member of FIG. 6A.

FIG. 6D is a schematic of the compression member of FIG. 6B.

FIG. 7 is a bottom view of the sole structure, showing the compression members coupled to the midsole plate.

FIGS. 8A and 8B are bottom views of the article of footwear.

Like numbers have been used to identify like components throughout the disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Turning to FIGS. 1A, 1B, 2A, 2B, 3A, and 3B an article of footwear 10 is an athletic shoe and, in particular, a running shoe. The article of footwear 10 includes an upper 105 and a sole structure 110 that cooperate to define several footwear regions corresponding with various parts of a foot. Specifically, the article of footwear 10 defines a rear footwear region 115 generally corresponding with the rear of the foot (e.g., the hindfoot including the heel); an intermediate footwear region 120 disposed forward the rear region and generally corresponding to the midfoot (e.g., the arched bottom and upper instep areas of the foot); and a forward footwear region 125 disposed forward of intermediate region and generally corresponding to the forefoot (e.g., the ball and toes of the foot).

The upper 105 includes a heel 130, a lateral side 135, a medial side 140, an instep 145, and a toe cage or box 150. The heel 130 forms a rear portion of upper 10 and is generally configured to extend along the heel of the foot. The lateral side 135 spans through a longitudinal length of footwear 10, being configured to extend along the lateral side of the foot. Similarly, the medial side 140 spans a longitudinal length of footwear, being configured to extend along the medial side of the foot. The instep 145, positioned between the lateral side and the medial side, generally extends along the instep of the foot. Finally, the toe cage 150 defines the forward area of the upper 105, being configured to house the toes of the foot.

The upper 105 forms a cavity that receives the foot. Specifically, the heel 130, lateral side 135, medial side 140, instep 145, and toe cage 150 cooperate to define an interior cavity into which a foot is inserted by way of an access opening or collar 155.

Various materials are suitable for upper 105, including leather, synthetic leather, rubber, textiles, and polymer foams, for example, that are stitched or adhesively bonded together. The specific materials utilized are generally selected to impart wear-resistance, flexibility, air-permeability, moisture control, and comfort to the article of footwear.

Referring to FIGS. 3A, 3B, and 3C, the sole structure 110 includes an insole (not illustrated), a midsole 305, an attenuation system 310, an outsole 315, and an optional heel counter 320. The insole is a thin cushioning layer located within the upper 105 such that it is positioned proximate the plantar surface of the foot to enhance footwear comfort. In accordance with the invention, the midsole 305 is a plate that spans the length of the upper to support the foot through its range of motion. The upper 105 may be coupled (e.g., attached) to the midsole plate 305 via adhesives, welding, etc. In an embodiment, the midsole plate 305 is a unitary structure formed of a hardened, flexible material such as a polymer (i.e. a non-foam material). By way of example, the midsole plate 305 is formed of a thermoplastic elastomer such as polyether block amide (e.g., PEBAX amides, available from Arkema Technical Polymers Division, Paris France) or thermoplastic polyurethane (TPU), e.g., a TPU having a Shore A value of about 95. By way of specific example, the midsole plate 305 may be formed of a polyether block amide having a Shore D hardness of about 50.

As shown in FIGS. 4A, 4B, and 4C, the midsole plate 305 is generally contoured to the shape of the foot, defining a top, user- or upper-facing side 405 and a bottom, ground-facing side 410. The heel counter 320 is a support contoured to cradle the heel of the wearer, extending along the lateral and medial sides of the heel, cupping it to limit the lateral, medial, and rearward movement of the foot and prevent misalignment during the step cycle. In an embodiment, the midsole plate 305 and the heel counter 320 are a unitary (one-piece) structure. In another embodiment, the heel counter and midsole plate are separate components formed of the same polymer. In still another embodiment, the heel counter 320 and midsole plate 305 are formed of different materials (e.g., different polymers of the same polymer of different Shore values). For example, the heel counter 320 may be formed of a polyether block amide, or may be formed of polyurethane having a Shore A value of 95. The top side 410 of the midsole plate 305 is generally flat, curving upward (toward the user) at its outer edges to define walls 415 operable to limit the movement (transverse and longitudinal movement) of the foot on the midsole plate 305.

As noted above, the midsole plate 305 may possess a uniform degree of flexure throughout its structure. Accordingly, when increased stiffness along the plate 305 is desired, a reinforcing member may be mounted to the plate. Referring to FIG. 4A and 3C, in an embodiment, the top side 405 of midsole plate 305 includes a recess 415 into which an insert or reinforcing member 420 is positioned. The reinforcing member 430 configured to limit the degree of flexure of the midsole plate 305. As shown, the reinforcing member is positioned along the top side 405 of the midsole plate 305 such that it spans the intermediate portion of the sole structure, being generally flush with the surface of the top plate side 405. Accordingly, the reinforcing member is disposed within the intermediate portion of the article of footwear 10, extending along the arch of the foot. In an embodiment, the reinforcing member 420 may be a fiberglass reinforced polyamide. With this configuration, flexure of the midsole plate 305 is limited (e.g., lessened) within the reinforced area of the midsole plate, and thus along the arch of the foot.

In another embodiment, the reinforcing element may be mounted on the insole. Referring to FIGS. 5A and 5B, the insole 505 inserted into the interior of the upper includes a reinforcing element 510 in the form of a plate secured to the bottom 515 of the insole. The plate spans the rear portion of the insole 505 (e.g., it spans the arch to the heel areas of the foot), and includes an aperture 520 disposed proximate the heel. As with the above embodiment, the reinforcing member 520 is formed of a polymer having a predetermined hardness value, and the reinforcing member 520 is positioned along the insole such that it spans the arch of the foot.

The midsole plate 305 of the reinforcing member 420 may be selectively modified to increase flexibility. Specifically, as seen in FIG. 4A, the midsole plate 305 and the reinforcing member 420 may include one or more transverse notches 425 that define weakened areas, along with controlled flexure may occur.

The bottom side 410 of the midsole plate 160 includes one or more receptacles adapted to receive a compression member. Referring to FIG. 4C, the midsole plate 160 includes a forward receptacle 425 positioned in the forefoot area 125 and a rearward receptacle 430 positioned in the heel or hind foot area 115. Each receptacle 425, 430 includes a plurality of cavities or sockets linked by channels. Specifically, the forward receptacle 425 includes front cavity 435 disposed proximate the toe cage in communication with a plurality (e.g., four) lateral cavities, namely, a first lateral cavity 440A, a second lateral cavity 440B, a third lateral cavity 440C, and a fourth lateral cavity 440D oriented along the lateral edge 442 of the midsole plate, and a plurality of (e.g., three) medial cavities, namely, a first medial cavity 445A, a second medial cavity 445B, and a third medial cavity 445C generally aligned along the medial edge of the support member. Each cavity 440A-440D, 445A-445C is in communication with adjacent cavities by a channel, specifically, a first lateral channel 450A, a second lateral channel 450B, a third lateral channel 450C, a fourth lateral channel 450D, a first medial channel 455A, a second medial channel 455B, and a third medial channel 455C.

Similarly, the rearward receptacle 430 includes a plurality of lateral cavities 460A (first rearward cavity), 460B (second lateral cavity), 460C (third lateral cavity) and a plurality of medial cavities 465A (first medial cavity), 465B (second medial cavity), 465C (third medial cavity). The lateral cavities of the rearward receptacle 430 are linked via lateral channels 470A, 470B, while the medial cavities are linked via medial channels 475A, 475B. The lateral and medial cavity sets are linked via an intermediate cavity 480.

The cavities and channels are defined by walls extending from the bottom surface 410 of the midsole plate 160. The cavities and channels may possess any dimensions suitable for their described purpose. As shown, the cavities are wider (longer in the transverse direction) than the channels. Additionally, the cavities may be longer (longer in the longitudinal direction) than the channels. The cavities may possess a generally polygonal shape, being contoured to receive the attenuation system (i.e., contoured similar to that of the compression members, which are discussed in greater detail below).

The attenuation system 310 is configured to provide selective cushioning to the wearer, as well as, in cooperation with the midsole plate 160, to provide for the flexure of the sole structure (e.g., to provide a predetermined flexure pattern to the structure). Referring to FIGS. 6A and 6B, the attenuation system 310 includes a forward compression member 605 (FIG. 6A) adapted to be received in the forward receptacle 425 and a rearward compression member 610 (FIG. 6B) adapted to be received by the rearward receptacle 430. Referring to FIG. 6A (showing the ground-facing side of the compression member), the forward compression member 605 possesses a generally U-shaped structure with by a median section defined by a front compression (or toe cage) element 615, a lateral arm or section 617 extending distally from the front compression element, and a medial arm or section 620 extending from the front compression element. As shown, the lateral 617 and medial 620 arms are spaced from each other. The lateral arm may be generally arcuate, curving medially toward its distal end. The medial arm 620 may be slightly arcuate, curving laterally toward its distal end.

The lateral arm or section 617 includes a plurality of lateral compression elements adapted to flex relative to each other. Specifically, the lateral section includes a first lateral compression element 625A coupled to the front compression element 615, a second lateral compression element 625B coupled to the first lateral compression element, a third lateral compression element 625C coupled to the second lateral compression element, and a fourth lateral compression element 625D coupled to the third lateral compression element.

Similarly, the medial section 620 includes and a plurality of medial compression elements moveably coupled to each other. Specifically, the medial section 620 includes a first medial compression element 630A coupled to the front compression element 615, a second medial compression element 630B coupled to the first medial compression element, and a third medial compression element 630C coupled to the second medial compression element.

The compression elements may possess any dimensions (size/shape) suitable for their described purpose. In an embodiment, the compression elements possess a generally polygonal shape. By way of example, one or more compression elements may possess a V-shape defined by a first arm oriented at an angle with respect to a second arm. Each compression element may form a unitary (one-piece) structure, or may be a plurality of individual segments.

The cross section of each compression element may vary relative to the others, the cross section being selected based upon the location of the element within the member. For example, one or more (e.g., all) of the lateral compression elements 625A-625D of the forward compression member 605 taper inward in the ground direction. Stated another way, the side walls of each lateral compression element may taper inward in the distal direction (from the support element toward the contact surface or ground) such that the distal end of the compression element is narrower than its proximal (midsole-plate-facing) end.

In contrast, one or more of the medial compression elements may taper outward. That is, the side walls of the medial compression elements may taper outward in the distal direction (in the direction away from the midsole pate bottom side 410) such that the distal end is wider than the proximal end. It should be understood, however, that the elements may taper in any desired manner.

The compression members 605, 610 including linking elements that couple a compression element 625A-625D, 630A-630C to an adjacent element. Specifically, a first lateral linking element 635A connects the front compression element 615 to the first lateral compression element 625A, a second lateral linking element 635B connects the second lateral compression element 625B to the first lateral compression element, a third lateral linking element 635C connects the third lateral compression element 625C to the second lateral compression element, and a fourth lateral linking element 635D connects the fourth lateral compression element 625D to the third lateral compression element.

Similarly, a first medial linking element 640A connects the front compression element 615 to the first medial compression element 630A, a second medial linking element 640B connects the second medial compression element 630B to the first medial compression element, and a third medial linking element 640C connects the third medial compression element 630C to the second medial compression element.

The linking elements 635A-635D, 640A-640C may possess any dimensions suitable for their described purpose. In an embodiment, the linking elements possess a generally triangular cross section (e.g., a triangle with rounded points), with the top of the triangle being oriented toward the ground. Additionally, the distal end of the linking element may be recessed relative to its adjacent compression elements (i.e., the linking element distal surface is not flush with the distal surface of the compression elements).

Referring to FIG. 6B, the rearward compression member 610 may be a generally U-shaped structure including a lateral arm or section 650 oriented toward the lateral side of the shoe and a medial arm or section 655 oriented toward the medial side of the shoe. The arms are connected via a transverse linking element 660 that defines the median section of the structure (i.e., the bend of the “U”). As with the forward compression member 605, each arm 650, 655 includes a plurality of compression elements coupled to each other via linking elements. Specifically, the lateral arm 650 includes a first lateral compression element 665A connected to a second lateral compression element 665B via a first lateral linking element 670A, and a third lateral compression element 665C is connected to the second lateral compression element via a second lateral linking member 670B. Similarly, the medial arm 655 includes a first medial compression element 675A connected to a second medial compression element 675B via a first medial linking element 680A, and a third medial compression element 675C connected to the second medial compression element via a second medial linking member 680B.

The linking elements of the forward 605 and rearward 610 compression members may be dimensioned to permit a selected degree of flex among the compression elements. Specifically, the linking elements may function as stabilizer bars that permit limited upward and downward movement of the elements relative to each other, while preventing/minimizing lateral and/or rotational movement of the members. In this manner, the compression elements are stabilized, which, in turn controls flexure along the compression member (discussed in greater detail below).

Additionally, the linking elements may be capable of transferring energy between the compression elements. Thus, when a load is applied to a compression element (e.g., via engagement with the ground that occurs during heel and midfoot strike, as well as toe-off), that load may be transferred from the engaged compression element to a disengage element (one that has not yet contacted the ground). Accordingly, the load may be dispersed along the compression member.

Each compression member 605, 610 may be formed of a compressible material such as foam (e.g., ethylene vinyl acetate foam). In general, the properties of the compression material may be any suitable for its described purpose (as explained below). By selecting a material with desired properties (e.g., Shore value or density), the relative stiffness and degree of ground reaction force attenuation may be selected to meet the specific demands of the activity for which the footwear is intended to be used.

As shown, each compression member 605, 610 possesses a unitary (one piece) structure having a uniform composition. It should be understood however, that other materials may be utilized and that the compression members may be multiple piece structures.

As noted above, the linking elements 635A-635D, 640A-640C, 660, 670A-670B, 680A-680B may be dimensioned to permit a selected degree of flex among the compression elements 625A-625D, 630A-630C (e.g., between adjacent compression elements) and, accordingly, define a flex pattern along each respective compression member 605, 610. For example, linking members 635A-635D, 640A-640C, 660, 670A-670B, 680A-680B may be formed of the same material, but may have different cross sectional volumes or thicknesses. Increasing the thickness of a linking member will stiffen the connection between adjacent compression elements, which, in turn, lessens the degree of flexure (up/down and/or lateral movement) between the adjacent elements (i.e., the flexure range of a thicker linking element is lower than the flexure range of a thinner linking element). Conversely, decreasing the thickness of a linking member 635A-635D, 640A-640C, 660, 670A-670B, 680A-680B increases the flexure between the linked compression elements.

In an embodiment, the degree of flexure may vary along the forward compression member 605. For example, the third medial linking element 640C may permit a lower degree of flexure between the second 630B and third 630C medial compression elements (indicated by FM1 in FIG. 6C) than the second medial linking element 640B permits between the second 630B and first 640A medial compression elements (indicated by FM2). Stated another way, the third medial linking element possesses a lower degree of flexure than the second medial linking element). In turn, the second medial linking element 640B permits less flexure between the second 630B and first 630A medial compression elements than the first medial linking element 640A permits between the first lateral compression element 630A and the front compression element 615 (indicated by FM3).

Accordingly, the degree of flexure between compression elements on the medial arm 620 of the forward compression member 605 increases in the forward direction (approaching the front compression element 615). Stated another way, the relative movement of adjacent medial compression elements 630A-630C in the forward compression member 605 increases toward the front of the shoe (such that FM1<FM2<FM3, with F being range of flexure between medial compression elements).

Similarly, the degree of flexure of lateral arm 617 may increase in the forward direction. Specifically, the degree of flexure provided by the lateral linking elements 635A-635D may increase in the forward direction, with the fourth lateral linking element 635D providing a lower range of flexure than the third lateral linking element 635C, the third lateral linking element providing lower flexure than the second lateral linking element 635B, and the second lateral linking element providing lower flexure than the first lateral linking element 635A. Thus FL1<FL2<FL3<FL4, with F being the degree of flexure permitted.

In addition, the comparative flexures between the lateral compression elements 625A-625D and the medial compression elements 630A-630C may differ. Specifically, the flexure between one or more pairs of adjacent lateral compression elements 625A-625D may be less than the flexure permitted between adjacent medial compression elements 630A-630C. Accordingly, the overall flexure of the medial arm 620 is less than the overall flexure of the lateral arm 617. With this configuration, movement of the forefoot is encouraged in the medial direction, but resisted in the lateral direction. This assists the natural movement of the foot, lessening fatigue and injury (explained in more detail below).

As with the forward compression member, the rearward compression member may have a predetermined flexure pattern. Specifically, the linking elements may be selectively sized to permit the movement of compression elements relative to each other. In general, the rearward compression elements undergo less flexure than the forward compression elements (increasing flexure of rearward compression member 610 indicated by arrow FI. For example, referring to FIG. 6D, LF1<LF2 (LF referring to flexure range of linking element), while in the medial arm 655, MF1<MF2 (MF referring to flexure range of linking element).

It should be understood, however, that the compression members may possesses any desired flexure pattern. The flexure of each of the forward and rearward compression elements, moreover, may be generally consistent throughout the member.

Referring to FIG. 7, the forward compression member 605 is received by the forward receptacle 425 of the midsole plate 160, while rearward compression member 610 is received by the rearward receptacle. As shown, each compression element is positioned within a corresponding cavity or socket and each linking element is positioned within a corresponding channel. As explained above, the receptacles and, in particular, each compression and linking element, is contoured to the dimensions of the cavities and channels.

With the above configuration, the attenuation system 310 may control the amount of flexure/bending that occurs between adjacent compression elements during a step cycle, which, in turn, regulates the overall flexure pattern of the compression member. One cause of premature fatigue of joints and/or muscles during exercise relates to the improper orientation of the foot during a step cycle. During a step, the average person tends to first contact the ground with the heel and subsequently rolls-off off the heel using the ball of the foot. A typical gait cycle for running or walking begins with a “heel strike” and ends with a “toe-off.” During the gait cycle, the main distribution of forces on the foot begins adjacent to the lateral side of the heel (outside of the foot) during the “heel strike” phase of the gait, then moves toward the center axis of the foot in the arch area, and then moves to the medial side of the forefoot area (inside of the foot) during “toe-off.” Many people slightly turn their foot from the outside to the inside between the first ground contact with the heel and pushing-off with the ball of the foot. That is, a person's center of mass typically is located more on the lateral side of the foot, but it tends to shift to the medial side during the course of the step cycle (this shifting to the medial side is called pronation). While some pronation is expected, excessive pronation can lead to increased strain on the joints and premature fatigue or even injury. Supination (shifting a foot laterally) may also occur during the step cycle. Supination may also result in increased strain and premature fatigue. Therefore, it is desirable to control the degree of turning of the foot during a step cycle.

Accordingly, the compression member may be configured to guide the foot during the step cycle by resisting supination and permitting a limited degree of pronation. Specifically, the flex pattern of the compression member may be configured such that, at heel strike, the lateral compression elements of the rearward compression member, while attenuating ground forces, do not easily flex due to the configuration of the lateral linking elements. Thus, upon heel strike, the heel is stabilized since the compression elements will independently flex to a limited degree to support the foot on the running surface. This stabilization occurs regardless of the incident angle of the heel strike, since each compression element compresses independently of other compression elements.

After heel strike, however, the foot rolls forward, landing on the forward compression pad. As noted above, the medial compression elements of the forward compression member flex more easily than the lateral compression element. Accordingly, the roll of the foot is directed medially, toward pronation, as indicated by arrow P in FIG. 8B. That is, should the foot begin lateral rotation, the flexure of the lateral side, while attenuating ground forces, resists this rotation. Instead, the foot takes the path of least resistance, rolling medially.

In addition to controlling flexure, the compressive ability of the members 605, 610 absorb and disperse the load caused by impact with the ground, attenuating the forces on the feet.

The sole structure may further include an outsole. Specifically, outsole material 805 may be disposed on the distal end of each compression element. Outsole material provides increased wear resistance and traction during use. By way of example, the outsole material may be rubber and may include protrusions 810 to aid in traction.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. It is to be understood that terms such as “top,” “bottom,” “front,” “rear,” “side,” “height,” “length,” “width,” “upper,” “lower,” “interior,” “exterior,” “medial,” “lateral,” and the like as may be used herein, merely describe points of reference and do not limit the present invention to any particular orientation or configuration. 

We claim:
 1. An article of footwear defining a longitudinal axis, the article of footwear comprising: an upper possessing a shoe length; and a sole structure coupled to the upper, the sole structure including: a midsole plate coextensive with the upper, the midsole plate defining a first, upper-facing side and a second, ground-facing side; a cavity formed into the second side of the midsole plate; and a compression member partially disposed within the cavity such that it depends from the second side of the midsole plate.
 2. The article of footwear of claim 1, wherein the compression member comprises compression material that compresses under load.
 3. The article of footwear of claim 2, wherein the compression material is foam.
 4. The article of footwear of claim 1, wherein: the midsole plate defines a plurality of cavities formed into the second plate side; and the compression member comprises a plurality of compression elements, each compression element being operably coupled to a corresponding plate cavity.
 5. The article of footwear of claim 4, wherein adjacent compression elements of the compression member are connected via a compressible linking element.
 6. The article of footwear of claim 5, wherein each compression element is a unitary structure formed of compression material.
 7. The article of footwear of claim 1, wherein: the compression member extends distally from the midsole plate; and the sole structure further comprises an outsole layer connected to a distal end of the compression member.
 8. The article of footwear of claim 1, wherein the compression member possesses areas of differing flexibility. 